Manufacture of pulp rovings



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I Nov. 15 1932.

J. c. SHERMAN MANUFACTURE OF PULP ROVINGS Filed June 6, 1951 Patented Nov. 15, 1932 UNITED STATES PATENT OFFICE JOHN C. SHERMAN, OF GORHAM, MAINE, ASSIGNOR TO BROWNOOMPANY, OF BERLIN,

NEW HAMPSHIRE, A CORPORATION OF MAINE MANUFACTURE OF PULP ROVINGS Application filed et, 1931. Serial No. 542,646.

This invention relates to the manufacture of pulp rovings, for instance from wood pulp, and has forits object to provide continuity of operation beginning with an aqueous pulp suspension and terminating with an accumulated mass in desirable form for subsequent twisting and plying into yarns and string. c

In accordance with the present invention, the pulp is deposited from aqueous suspension on a travelling wire cloth as spaced con tinuous ribbons, dewatering to the proper moisture content, are furled or rolled out into rovings and are delivered into a so-called spinning pot and are collected as annular masses easy to handle and permitting subsequent rewinding, twisting and plying into yarns or string. I have found that despite the dampness and tenderness of the rovings or strands, they are, never-- theless, amenable to collection without breakage in a spinning pot of the same general type used in pot-spinning or artificial silk, and further that little if any stickiness or matting of the roving continuously convoluted as a succession of layers takes place, despite the dampness of the accumulation. This finding is surprising especially when one stops to reflect that the pulp rovings in damp condition are of much lower tensile strength than artificial silk,- so much so, that heretofore it was taken for granted that accumulations had to be effected as on a bobbin or spool whose peripheral speedwas synchronized with the speedof the forming wire.

With the foregoing and other features and objects in view, my invention will now be described in conjunction .with the accompanying drawing wherein:

Figure 1 shows more or less diagrammatically and conventionallya side View of an apparatus embodying the present invention.

Figure 2 is a plan view of the same.

which, after undergoing are separated from their forming support Figure 3 is a front elevation of the apparatus. 1

Figure 4 illustrates a section through a spinning-pot having amaccumulation of roving therein.

As shown in Figure 1, the apparatus includes generally an endless wire cloth 1, a suction roll 2 about which the cloth passes, and a pulpvat 3 inwhich the suction roll rotates partially submerged. An aqueous pulp suspension is continuously delivered from a supply pipe 4 into the vat near its rear wall at a volumetric rate sufiicient to maintain thesuction roll partially submerged, the suspension flowing forwardly under a bafile 5 to ward the suction roll 2 and the overlying wire cloth -1. The roll is provided with spaced peripher-al grooves (not shown) communicating with its hollow interior, so that as the pulp suspension contacts with the travelling wire, water is progressively removed therefrom and pulp fibers are continuously deposited as spaced continuous ribbons on the wire. As shown, water passing into the rollhollow is removed therefrom by a suction pipe 6 entering into the hollow through one of the roll-trunnions '7 journaled in the side walls of; the vat. The spaced narrow Pulp deposits or ribbons 8 are carried out o the pulp suspension by the wire, which then proceeds horizontally over one or more suction boxes 9 designed to effect 'dewatering of the ribbons to a moisture content, say, about 250%, at which their furling into round bodies or rovings can be accomplished most advantageously. The ribbons may then be furled or rolled out in any suitable manner. As shown, the wire takes. a downward course about a terminal roll 10 at which the ribbons and pass vertically downward to furling means presently to be described. The wire then completes its circuit by passing over a guide roll 11 and thence under the suction roll 2.

The furlin mechanism illustrated consists of a pair of rictionally confronting belts 12 arranged to receive therebetween the ribbons leaving the wire. Each belt is supported by a pair of terminal rolls 13, one or more of which may be driven by suitable means (not shown) and thus serve to propel the belts. Each pair of terminal rolls associated with a belt is arranged at an angle to the other pair, so that the resultant of motion between the belts is at an angle to the vertical and further so that the ribbons of pulp frictionall engaged between the contacting belt sur aces are progressively furled or rolled out in the direction of this resultant of motion. As shown, both pairs of rolls 13 are preferably arranged at a slight angle to the horizontal with one pair at a positive angle and the other air at a corresponding negative angle, there by affording a resultant angularit of motion between the. confronting belt sur aces equal to the sum of both angles. The damp ribbons leaving the forming wire vertically are received between the frictionally confronting .belt surfaces and are furled or rolled out into round bodies or strands 14. The dam strands are led into spinning pots 15, whic as shown in Figure 1, are in staggered array in order to avoid a line of pots of inordinate length. If desired, each strand may be directed to its independent pot by the use of a neumatic system, such as described and c aimed in application Serial No. 504,029, filed December 22, 1930, by

' Milton 0. Schur.

Each strand issuing from between. the furling belts is led into the spinning pot 15 under conditions to produce an annular mass 16 ofdamp roving as illustrated in Figure 4.- The pot 15 is rotated or spun by suitable means (not shown) at sufiiciently high speed to deposit the roving by centrifugal action aga nst the wall of the pot or against such roving as has already been deposited to form a compact, annular mass or package. The annular mass or package is built up, as is well known to.those skilled in the art, by effecting a relative vertical traverse between spinning pot and the roving being delivered to the pot. To this end, the spinning pot may be reciprocated vertically or, as shown,

the roving may be caused to pass through-a reciprocating vertical funnel 17 whose lower or elivery end is ositioned axially in the pot and-traverses t e depth of the pot.

The instrumentalities hereinbefore de.

scribed are subject to modification while still falllngwithin the purview of my invention, WlllCh 1s not limite to any particular means for forming ribbons of pulp on the travelling wire or means for furling or rolling out the ribbons. The travelling wire support or formmg means gives rise to pulp ribbons composed of interfelted fibers whose lay is preponderantly longitudinal; and the ribons can be supported on the wire until they are dewatere'd to the moisture content desired for furling. It is, however, possible to effect the furling of the ribbons while they are still on the forming wire by a furling dandy roll or equivalent roll, as described and claimed in application Serial No. 542,649, filed June 6, 1931, by Milton 0. Schur and William B. Meglitz. My invention resides in the broad combination including as a necessary element the spinning pot, which possesses the advantage ofnot only accumulatin the continuous damp roving in a desirab e form but which permits automatic accumulation at high speeds of manufacture, for instance, at speeds of 500 feet or more per minute. During accumulation in the spinning pot there ismore or less twisting of the roving, depending upon the speed of the pot. In any event, the speed of the internal wall of the pot, whether the wall is that of the pot proper or the wall formed by the already accumulated roving, is much greater than the linear rate of production of the roving so as to ensure centrifugal deposition of the roving. It isthus seen that flexibility or leeway in the rate of roving production is bad without the necessity of synchronizing the speed of roving production with the speed of the spinning pot, other than ensuring a fixed minimum speed of rotation of the pot conducive to the formationof an annular and more or less compact mass of roving.

The mass of damp roving collected in the spinning pot should be kept moist for subsequent twisting and plying operations, for which purpose, it is necessary to subject the mass promptly to such operations or to store or keep the mass while at the same time preventing the evaporation of much moisture therefrom. My method may be carried out conveniently in a pulp mill, but in some cases, the accumulated step product or package resulting from my method may be placed in hermetically sealed containers and shipped to a textile mill for subsequent manufacturing steps. The step-product of the present invention, however, being compact and easy to handle, constitutes an excellent form in which it can be stored or shipped.

I claim:

1. A method which comprises progressively depositing from aqueous pulp suspension on an endless travelling wire cloth a series of continuous pulp ribbons, progressively furling the damp ribbons into rovings, and progressively leading the damp rovings into spinning pots under conditions to build up compact annular :masses from which the rovings may be progressively withdrawn.

2. s astep-product, a compact annular mass or package consisting entirely of damp pulp roving continuously convoluted as a succession of layers from which the roving may be progressively withdrawn.

3. As a step-product, a compact annular mass or packa e consisting entirely of previously-furled, amp pulp ribbon continuously convoluted as a succession of layers from which such furled ribbon'may be progressively withdrawn.

4. As a step product, a compact annular mass or package consisting entirely of damp pulp roving having a moisture content of about 250%, continuously convoluted as a succession of layers from which the roving may be progressively withdrawn.

In testimony whereof I have afiixed my signature.

JOHN C. SHERMAN. 

